Question

What happens when you mix silver nitrate and potassium chromate?

Answer 1

Hint: This is a displacement reaction, in this kind of reaction, more reactive element displaces a less reactive element. Generally this reaction is used in labs to show precipitation of silver chromate. This reaction can even be done in a test tube.

Complete answer:
The correct answer to this question is that when you mix silver nitrate and potassium chromate, precipitates of silver chromate appear. And potassium nitrate is formed as a by-product.
The chemical formula of silver nitrate is $$AgN{O}_3$$ and the chemical formula for potassium chromate is $$K_{2}Cr{O}_4$$ . The reaction that occurs when you mix silver nitrate with potassium chromate is given below,
 $$2AgN{O}_3(aq)+K_{2}Cr{O}_4(aq)\to A{g}_{2}Cr{O}_4(s)+2KN{O}_3(aq)$$
Here, silver displaces potassium from chromate or vice-versa, thus forming silver chromate and potassium nitrate. This is a displacement reaction in which the more reactive element displaces the less reactive element. To balance the equation, 2 molecules of silver nitrate are taken and only one molecule of potassium chromate is taken.
The ionic reaction of silver and nitrate is given below.
 $$2A{g}^{+}+Cr{O}_4^{2-}\to A{g}_{2}Cr{O}_4$$
At the start of the reaction, both the reactants are in aqueous form, but after the reaction is completed silver nitrate is precipitated in solid form and potassium nitrate remains in aqueous form.

Note:
The colour of the precipitates of silver nitrate may vary depending upon the concentrations of the reactants, but white colour or red colour precipitates may be obtained many times. Nitrate salts are generally soluble in water and thus silver nitrate salt is used here to get silver ions in the solution.